In food service industry, during the course of transferring products from either cold storage or normal cooking status to some designated place, food safety is a big concern. Regulatory authority and the food service industry have established that potentially hazardous food products maintained either below 40.degree. F. or above 140.degree. F. are generally safe from the growth of potentially dangerous bacteria. Thus, the temperature window roughly between 40.degree. F. and 140.degree. F. can be considered to be a danger zone. To ensure food safety, a simple and effective inspection method for monitoring food temperature and then alerting if food temperature is in a danger zone is desired.